West African Groundnut and Sweet Potato Soup

the sustaining soup of Senegambia and the Guinea coast: sweet potato and tomatoes simmered in a rich groundnut (peanut) base deepened with tomato paste, spiced with ginger and chilli, and finished with leafy greens — a deeply savoury, warming one-pot with African roots and a global reach

Origin: Senegambia and the Guinea Coast, West Africa

From the journey of Sweet Potato.

Groundnut soup (the broad family of West and Central African stews based on a peanut paste or peanut butter thinned into a broth with tomatoes and spices) is one of the most widely distributed and deeply rooted cooking traditions on the African continent, stretching from Senegal and Gambia in the west through Guinea, Sierra Leone, and Ghana to the Democratic Republic of Congo in the centre. The addition of sweet potato to the groundnut base is particularly characteristic of the Senegambia region, where Portuguese traders introduced Ipomoea batatas around 1580 and it was immediately integrated into the existing agricultural and culinary tradition. The encounter between the sweet potato and the groundnut in West African cooking produced a combination that has proved extraordinarily durable: the sweetness and starch of the potato tempering and thickening the rich, slightly oily groundnut broth; the groundnut providing the protein and fat that the root vegetable lacks. This combination (sweet starchy root with legume paste in a spiced tomato broth) was carried across the Atlantic by enslaved Africans and gave rise, in various forms, to the peanut-and-sweet-potato preparations of the American South and the Caribbean. The version presented here follows the Senegambian tradition of including whole pieces of sweet potato that retain their shape in the finished stew, rather than being dissolved into the sauce as a thickener, and of finishing with leafy greens (traditionally cassava leaves, spinach, or sweet potato leaves) that are stirred in at the last moment.

Ingredients

Soup

2 tbsp neutral oil or palm oil
1 large onion, finely chopped
4 garlic cloves, finely chopped
1 thumb fresh ginger, peeled and grated (about 2 tsp)
1 Scotch bonnet or habanero chilli, pierced but left whole (remove before serving for moderate heat)
2 tbsp tomato paste
400 g tinned chopped tomatoes
160 g smooth peanut butter (unsweetened, natural)
800 ml vegetable or chicken stock
600 g orange-fleshed sweet potatoes, peeled and cut into 4 cm chunks
1 tsp fine salt, plus more to taste
100 g baby spinach, sweet potato leaves, or kale (tough stems removed), roughly chopped
1 tbsp lemon or lime juice

To Serve

3 tbsp roasted peanuts, roughly chopped, to garnish
1 Scotch bonnet chilli, thinly sliced, to garnish (optional)

Method

Heat the oil in a large pot over medium heat. Add the onion and cook, stirring, for 8–10 minutes until soft and golden. Add the garlic and ginger and cook for a further 2 minutes until fragrant.
Add the tomato paste and stir it into the onion mixture. Cook for 2 minutes, stirring, until the paste has darkened slightly. Add the chopped tomatoes and the whole Scotch bonnet chilli. Cook over medium heat, stirring occasionally, for 8–10 minutes until the tomatoes have broken down and the mixture is thick.
Stir in the peanut butter until it is fully incorporated into the tomato base. Gradually add the stock, stirring until smooth. Bring to a simmer.
Add the sweet potato chunks and the salt. Simmer uncovered over medium-low heat for 20–25 minutes until the sweet potato is completely tender and the broth has thickened to a rich, coating consistency. Taste and adjust salt; add the lemon juice.
Add the leafy greens and stir through. Cook for 2–3 minutes until just wilted. Remove the Scotch bonnet if still present. Serve over white rice or with flatbread, garnished with the chopped peanuts and sliced chilli.

Notes

Palm oil gives a more authentic West African flavour and the characteristic deep orange-red colour of the groundnut soup tradition; neutral oil produces a more neutral result. Unsweetened natural peanut butter is essential; do not use sweetened peanut butter, which will throw the flavour completely. The soup thickens considerably on standing; add a splash of water when reheating. It keeps well refrigerated for 3 days and improves overnight.

The Gastrographer

Name: West African Groundnut and Sweet Potato Soup
Prep time: 20 min
Cook time: 45 min
Total time: 1 h 5 min
Yield: 4
Cuisine: West Africa
Ingredients: 2 tbsp neutral oil or palm oil; 1 large onion, finely chopped; 4 garlic cloves, finely chopped; 1 thumb fresh ginger, peeled and grated (about 2 tsp); 1 Scotch bonnet or habanero chilli, pierced but left whole (remove before serving for moderate heat); 2 tbsp tomato paste; 400 g tinned chopped tomatoes; 160 g smooth peanut butter (unsweetened, natural); 800 ml vegetable or chicken stock; 600 g orange-fleshed sweet potatoes, peeled and cut into 4 cm chunks; 1 tsp fine salt, plus more to taste; 100 g baby spinach, sweet potato leaves, or kale (tough stems removed), roughly chopped; 1 tbsp lemon or lime juice; 3 tbsp roasted peanuts, roughly chopped, to garnish; 1 Scotch bonnet chilli, thinly sliced, to garnish (optional)

Mapping Culinary History

To explore — select an ingredient below.

To explore — select an ingredient below · click any location dot on the map for recipes and stories · browse the information panel on the right · trace the full journey on the timeline.

Journey Point Map Key

Ingredient originTrade or transit route

Became a culinary stapleColonial / trade control